Windows the operating system doesn't know anything about duplex. Because each manufacturer stores it's setting differently there is no way of extracting this information via WMI in a standard fashion. I can tell you that both Broadcom and Intel include SNMP agents that make this information available in their MIB. You would need to install the Intel or Broadcom software on the servers if it's not already, and be sure to include the SNMP agent which I believe is an optional component on the Intel software. Then you can create a universal device poller for all your servers with Intel NICs, and then another one for servers with Broadcom NICs, and so on. Hope this help.